Armenia’s Central Election Commission on December 13 said amendments to the country’s constitution have been adopted, a week after a national referendum, transforming the country from a presidential to a parliamentary system of government.

After announcing the final results from the December 6 referendum, all members of the commission voted unanimously for a resolution approving the amendments.

The commission also rejected allegations raised by the opposition Armenian National Congress (HAK) that the government secured support for the amendments through ballot-box stuffing, multiple voting, and vote buying.

HAK official Levon Zurabian claimed that the real turnout was less than half of eligible voters.

But the commission ruled on December 13 that “no violations that could impact the referendum results were reported.”

It said “a mere list of violations” reported from local election commissions “cannot be considered as grounds” for dismissing the results.

It said “legal evidence of their possible influence on the referendum results is needed.”

The opposition says the amendment is meant to enable President Serzh Sarkisian to remain in power after his final term as president ends in 2018.